accel.c 5.96 KB
Newer Older
1
2
3
4
5
6
7
8
9
10
11
12
13
#include <stdio.h>
#include <string.h>

#include <stm32f4xx_hal.h>

#include "misc.h"
#include "mpconfig.h"
#include "qstr.h"
#include "obj.h"
#include "runtime.h"
#include "accel.h"

#define MMA_ADDR (0x98)
14
15
16
17
#define MMA_REG_X (0)
#define MMA_REG_Y (1)
#define MMA_REG_Z (2)
#define MMA_REG_TILT (3)
18
#define MMA_REG_MODE (7)
19
#define MMA_AXIS_SIGNED_VALUE(i) (((i) & 0x3f) | ((i) & 0x20 ? (~0x1f) : 0))
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61

STATIC I2C_HandleTypeDef I2cHandle;

void accel_init(void) {
    GPIO_InitTypeDef GPIO_InitStructure;

    // PB5 is connected to AVDD; pull high to enable MMA accel device
    GPIOB->BSRRH = GPIO_PIN_5; // turn off AVDD
    GPIO_InitStructure.Pin = GPIO_PIN_5;
    GPIO_InitStructure.Mode = GPIO_MODE_OUTPUT_PP;
    GPIO_InitStructure.Speed = GPIO_SPEED_LOW;
    GPIO_InitStructure.Pull = GPIO_NOPULL;
    HAL_GPIO_Init(GPIOB, &GPIO_InitStructure);

    // PB6=SCL, PB7=SDA
    GPIO_InitStructure.Pin = GPIO_PIN_6 | GPIO_PIN_7;
    GPIO_InitStructure.Mode = GPIO_MODE_AF_OD;
    GPIO_InitStructure.Speed = GPIO_SPEED_FAST;
    GPIO_InitStructure.Pull = GPIO_NOPULL; // have external pull-up resistors on both lines
    GPIO_InitStructure.Alternate = GPIO_AF4_I2C1;
    HAL_GPIO_Init(GPIOB, &GPIO_InitStructure);

    // enable the I2C1 clock
    __I2C1_CLK_ENABLE();

    // set up the I2C1 device
    memset(&I2cHandle, 0, sizeof(I2C_HandleTypeDef));
    I2cHandle.Instance = I2C1;
    I2cHandle.Init.AddressingMode  = I2C_ADDRESSINGMODE_7BIT;
    I2cHandle.Init.ClockSpeed      = 400000;
    I2cHandle.Init.DualAddressMode = I2C_DUALADDRESS_DISABLED;
    I2cHandle.Init.DutyCycle       = I2C_DUTYCYCLE_16_9;
    I2cHandle.Init.GeneralCallMode = I2C_GENERALCALL_DISABLED;
    I2cHandle.Init.NoStretchMode   = I2C_NOSTRETCH_DISABLED;
    I2cHandle.Init.OwnAddress1     = 0xfe; // unused
    I2cHandle.Init.OwnAddress2     = 0xfe; // unused

    if (HAL_I2C_Init(&I2cHandle) != HAL_OK) {
        // init error
        printf("accel_init: HAL_I2C_Init failed\n");
        return;
    }
62
63
64
65
66
67
68
69
}

STATIC void accel_init_device(void) {
    // turn off AVDD, wait 20ms, turn on AVDD, wait 20ms again
    GPIOB->BSRRH = GPIO_PIN_5; // turn off
    HAL_Delay(20);
    GPIOB->BSRRL = GPIO_PIN_5; // turn on
    HAL_Delay(20);
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91

    HAL_StatusTypeDef status;

    //printf("IsDeviceReady\n");
    for (int i = 0; i < 10; i++) {
        status = HAL_I2C_IsDeviceReady(&I2cHandle, MMA_ADDR, 10, 200);
        //printf("  got %d\n", status);
        if (status == HAL_OK) {
            break;
        }
    }

    //printf("MemWrite\n");
    uint8_t data[1];
    data[0] = 1; // active mode
    status = HAL_I2C_Mem_Write(&I2cHandle, MMA_ADDR, MMA_REG_MODE, I2C_MEMADD_SIZE_8BIT, data, 1, 200);
    //printf("  got %d\n", status);
}

/******************************************************************************/
/* Micro Python bindings                                                      */

92
93
#define NUM_AXIS (3)
#define FILT_DEPTH (4)
94

95
96
97
98
typedef struct _pyb_accel_obj_t {
    mp_obj_base_t base;
    int16_t buf[NUM_AXIS * FILT_DEPTH];
} pyb_accel_obj_t;
99

100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
STATIC pyb_accel_obj_t pyb_accel_obj;

STATIC mp_obj_t read_axis(int axis) {
    uint8_t data[1];
    HAL_I2C_Mem_Read(&I2cHandle, MMA_ADDR, axis, I2C_MEMADD_SIZE_8BIT, data, 1, 200);
    return mp_obj_new_int(MMA_AXIS_SIGNED_VALUE(data[0]));
}

STATIC mp_obj_t pyb_accel_x(mp_obj_t self_in) {
    return read_axis(MMA_REG_X);
}

STATIC MP_DEFINE_CONST_FUN_OBJ_1(pyb_accel_x_obj, pyb_accel_x);

STATIC mp_obj_t pyb_accel_y(mp_obj_t self_in) {
    return read_axis(MMA_REG_Y);
}
117

118
STATIC MP_DEFINE_CONST_FUN_OBJ_1(pyb_accel_y_obj, pyb_accel_y);
119

120
121
STATIC mp_obj_t pyb_accel_z(mp_obj_t self_in) {
    return read_axis(MMA_REG_Z);
122
123
}

124
STATIC MP_DEFINE_CONST_FUN_OBJ_1(pyb_accel_z_obj, pyb_accel_z);
125

126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
STATIC mp_obj_t pyb_accel_tilt(mp_obj_t self_in) {
    uint8_t data[1];
    HAL_I2C_Mem_Read(&I2cHandle, MMA_ADDR, MMA_REG_TILT, I2C_MEMADD_SIZE_8BIT, data, 1, 200);
    return mp_obj_new_int(data[0]);
}

STATIC MP_DEFINE_CONST_FUN_OBJ_1(pyb_accel_tilt_obj, pyb_accel_tilt);

STATIC mp_obj_t pyb_accel_filtered_xyz(mp_obj_t self_in) {
    pyb_accel_obj_t *self = self_in;

    memmove(self->buf, self->buf + NUM_AXIS, NUM_AXIS * (FILT_DEPTH - 1) * sizeof(int16_t));

    uint8_t data[NUM_AXIS];
    HAL_I2C_Mem_Read(&I2cHandle, MMA_ADDR, MMA_REG_X, I2C_MEMADD_SIZE_8BIT, data, NUM_AXIS, 200);

    mp_obj_t tuple[NUM_AXIS];
    for (int i = 0; i < NUM_AXIS; i++) {
        self->buf[NUM_AXIS * (FILT_DEPTH - 1) + i] = MMA_AXIS_SIGNED_VALUE(data[i]);
        int32_t val = 0;
        for (int j = 0; j < FILT_DEPTH; j++) {
            val += self->buf[i + NUM_AXIS * j];
        }
        tuple[i] = mp_obj_new_int(val);
150
151
    }

152
    return rt_build_tuple(3, tuple);
153
154
}

155
STATIC MP_DEFINE_CONST_FUN_OBJ_1(pyb_accel_filtered_xyz_obj, pyb_accel_filtered_xyz);
156

157
158
159
160
161
162
163
164
165
166
167
168
STATIC mp_obj_t pyb_accel_read_reg(mp_obj_t self_in, mp_obj_t reg) {
    uint8_t data[1];
    HAL_I2C_Mem_Read(&I2cHandle, MMA_ADDR, mp_obj_get_int(reg), I2C_MEMADD_SIZE_8BIT, data, 1, 200);
    return mp_obj_new_int(data[0]);
}

MP_DEFINE_CONST_FUN_OBJ_2(pyb_accel_read_reg_obj, pyb_accel_read_reg);

STATIC mp_obj_t pyb_accel_write_reg(mp_obj_t self_in, mp_obj_t reg, mp_obj_t val) {
    uint8_t data[1];
    data[0] = mp_obj_get_int(val);
    HAL_I2C_Mem_Write(&I2cHandle, MMA_ADDR, mp_obj_get_int(reg), I2C_MEMADD_SIZE_8BIT, data, 1, 200);
169
170
171
    return mp_const_none;
}

172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
MP_DEFINE_CONST_FUN_OBJ_3(pyb_accel_write_reg_obj, pyb_accel_write_reg);

STATIC const mp_method_t accel_methods[] = {
    { "x", &pyb_accel_x_obj },
    { "y", &pyb_accel_y_obj },
    { "z", &pyb_accel_z_obj },
    { "tilt", &pyb_accel_tilt_obj },
    { "filtered_xyz", &pyb_accel_filtered_xyz_obj },
    { "read_reg", &pyb_accel_read_reg_obj },
    { "write_reg", &pyb_accel_write_reg_obj },
    { NULL, NULL },
};

STATIC const mp_obj_type_t accel_obj_type = {
    { &mp_type_type },
    .name = MP_QSTR_Accel,
    .methods = accel_methods,
};

STATIC mp_obj_t pyb_Accel(void) {
    pyb_accel_obj.base.type = &accel_obj_type;
    accel_init_device();
    return &pyb_accel_obj;
}

MP_DEFINE_CONST_FUN_OBJ_0(pyb_Accel_obj, pyb_Accel);